introduce kill_orphaned_pgrp() helper

Factor out the common code in reparent_thread() and exit_notify().

No functional changes.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 35 insertions, 39 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 506a957b665..11fcce76015 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -255,6 +255,37 @@ static int has_stopped_jobs(struct pid *pgrp)
         return retval;
 }
 
+/*
+ * Check to see if any process groups have become orphaned as
+ * a result of our exiting, and if they have any stopped jobs,
+ * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
+ */
+static void
+kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
+{
+        struct pid *pgrp = task_pgrp(tsk);
+        struct task_struct *ignored_task = tsk;
+
+        if (!parent)
+                 /* exit: our father is in a different pgrp than
+                  * we are and we were the only connection outside.
+                  */
+                parent = tsk->real_parent;
+        else
+                /* reparent: our child is in a different pgrp than
+                 * we are, and it was the only connection outside.
+                 */
+                ignored_task = NULL;
+
+        if (task_pgrp(parent) != pgrp &&
+            task_session(parent) == task_session(tsk) &&
+            will_become_orphaned_pgrp(pgrp, ignored_task) &&
+            has_stopped_jobs(pgrp)) {
+                __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
+                __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
+        }
+}
+
 /**
  * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
  *
@@ -635,22 +666,7 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
             p->exit_signal != -1 && thread_group_empty(p))
                 do_notify_parent(p, p->exit_signal);
 
-        /*
-         * process group orphan check
-         * Case ii: Our child is in a different pgrp
-         * than we are, and it was the only connection
-         * outside, so the child pgrp is now orphaned.
-         */
-        if ((task_pgrp(p) != task_pgrp(father)) &&
-            (task_session(p) == task_session(father))) {
-                struct pid *pgrp = task_pgrp(p);
-
-                if (will_become_orphaned_pgrp(pgrp, NULL) &&
-                    has_stopped_jobs(pgrp)) {
-                        __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
-                        __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
-                }
-        }
+        kill_orphaned_pgrp(p, father);
 }
 
 /*
@@ -738,8 +754,6 @@ static void forget_original_parent(struct task_struct *father)
 static void exit_notify(struct task_struct *tsk)
 {
         int state;
-        struct task_struct *t;
-        struct pid *pgrp;
 
         /*
          * This does two things:
@@ -753,25 +767,7 @@ static void exit_notify(struct task_struct *tsk)
         exit_task_namespaces(tsk);
 
         write_lock_irq(&tasklist_lock);
-        /*
-         * Check to see if any process groups have become orphaned
-         * as a result of our exiting, and if they have any stopped
-         * jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
-         *
-         * Case i: Our father is in a different pgrp than we are
-         * and we were the only connection outside, so our pgrp
-         * is about to become orphaned.
-         */
-        t = tsk->real_parent;
-
-        pgrp = task_pgrp(tsk);
-        if ((task_pgrp(t) != pgrp) &&
-            (task_session(t) == task_session(tsk)) &&
-            will_become_orphaned_pgrp(pgrp, tsk) &&
-            has_stopped_jobs(pgrp)) {
-                __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
-                __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
-        }
+        kill_orphaned_pgrp(tsk, NULL);
 
         /* Let father know we died
          *
@@ -788,8 +784,8 @@ static void exit_notify(struct task_struct *tsk)
          * the same after a fork.
          */
         if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 &&
-            ( tsk->parent_exec_id != t->self_exec_id  ||
-              tsk->self_exec_id != tsk->parent_exec_id)
+            (tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
+             tsk->self_exec_id != tsk->parent_exec_id)
             && !capable(CAP_KILL))
                 tsk->exit_signal = SIGCHLD;